Peter Kenyon, TunnelTalk

The city of Calgary in Canada is to investigate the feasibility of a 6km stormwater diversion tunnel. An expert panel convened in the wake of disastrous flooding earlier this year is granted Can$250,000 by the Province of Alberta to investigate the estimated $300 million project.

Calgary sits in the Bow River basin in a natural flood plain

In June this year (2013) Canada's third largest city was crippled by a 100-year flood event of the Elbow, High, Highwood and Bow Rivers that brought its central business district to a virtual standstill. The damage and clear-up cost in Calgary alone is estimated at £500 million, rising to $5 billion for damage to surrounding municipalities.

"We estimate that approximately 100 million cubic meters of water would have to be stored or retained in some fashion in order to mitigate the flooding that we experienced," said Richard Lindseth of Calgary’s Flood Mitigation Advisory Panel. "The proposed tunnel would travel from the western end of the Glenmore Reservoir to deposit water, in effect to bypass the Elbow River valley within the city, and deposit the water at the Bow River in a line that follows the alignment of 58th Avenue."

"If we can figure out the right way to do it, if we can figure out ways to share the capital cost, then we should do it," said Naheed Menshi, Mayor of Calgary.

Design and water resources consultants Aecom and WaterSMART have been retained to assist with investigating mitigating solutions, but the overriding plan is to turn ideas quickly into a design and construction phase rather than completing feasibility studies, many of which are already in existence.

Damage caused by the flood in Calgary is estimated at £500 million

At the Alberta Flood Mitigation Symposium Andre Corbould of the Alberta Flood Recovery Task Force, told delegates: "We have put out an RFP and we have hired two consulting engineers to help turn these concepts and ideas into actual engineering and I want to make sure you understand that of the seven elements we have consulted and are going forward with you don’t see the start of another study about flood proofing. We are not starting with more studies we are starting with taking these ideas and concepts from the many studies we already have and turning it into design and action."

Keynote speaker Scott Edelman, Senior VP of Aecom Water Resources and an expert who has given evidence about flood mitigation to the United Nations, said: "I have seen disasters across the globe and Alberta is ranking in the top ten per cent in how you are reacting to the flood. I am not seeing blame, what I am seeing is unbelievable cooperation. I am seeing leadership from the very highest level. You are having political support, political will and the funding to make this a better place. You have the ingredients to impact future generations."

In addition to the proposed tunnel, other mitigating measures include construction of berms, dykes, dams and sluice gates which together are expected to cost approximately $6 billion.

Add your comment

Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.